In recent years, in order to achieve safe and secure society, there are increasing needs for monitoring cameras that watch local societies on behalf of human eyes. It is important for monitoring cameras to improve visibility of videos. Image correction techniques such as blurring correction, gradation correction, or disturbance (rain, fog, smog, yellow sand, etc.) correction have been developed so far.
Heat haze is one of phenomena that reduces visibility of monitoring camera videos. Heat haze is a natural phenomenon that occurs from optical refraction that is caused by portions of atmosphere with different local densities mixed together. Heat haze is likely to be monitored when imaging asphalt of roads or car roofs using telescopic lens in high temperature days. When heat haze occurs, the imaged subject is monitored with deformed shapes. Accordingly, when reproducing the captured heat haze video, a specific portion in the captured image seems significantly wavered. Therefore, the visibility of the imaged subject is significantly reduced.
Patent Literature 1 listed below: determines whether a distortion occurs due to air fluctuation; if it is determined that the distortion due to air fluctuation occurs, creates a plurality of images by consecutive shooting; and adds up (averages) the plurality of images, thereby creating an image with the distortion being corrected.